The height of greenland is probably is due to it being the icecap rather than the underlying rock. Africa does seem unusually low though, along with the Indian subcontinent, south-east Asia, Australia and New Zealand.

I've made a few very pretty maps using the Tangram Heightmapper. In combination with Gimp and and a panorama photo combiner, re-exporting the image over and over, and then re-opening the map in Simutrans to get the heights right takes a while but provides satisfying results. The only issue is some pixels in the image create pyramids scattered over the map. Here is a map of Korea that I mocked up, with towns and industries maxed out.

I have a map of Spain (scale 125m/tile) and South Georgia (without the Sandwich Islands, roughly 125m/tile). The maps are 175MB uncompressed, but here are png copies (<10MB, expires in two weeks). Mountain heights are an issue as the maximum height from a height map seems to be 30 of 32 tiles, changing the conversion factor just makes the maps flatter.

edit: I've noticed the Spain map is broken on the western third. I'm sorry about that. If you're interested I can send the source images.